DTC Advanced Diagnostics: P0977
DTC P0977:Shift Solenoid Valve "B" Circuit High

General Description

Torque converter clutch status by shift solenoid valve B output
Torque Converter Clutch
Shift Solenoid Valve B
OFF
OFF
ON
ON

Shift solenoid valve B controls the drain circuit close/open commanded by the transmission control module (TCM) ON/OFF commands. Fluid passages which supply/discharge the hydraulic pressure to torque converter clutch is switched by shift solenoid valve B ON/OFF control. The TCM commands the driver circuit to turn on shift solenoid valve B. The circuit diagnoses malfunctions such as a circuit short or open, and sends back a return signal during the TCM's command. When the return signal does not match the TCM command to turn OFF shift solenoid valve B, the TCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
1 second or more
DTC Type
Two drive cycles, MIL on, Shift position indicator blinks

Enable Conditions
Condition
Minimum
Maximum
12 volt battery voltage [Battery Voltage]
10.0 V
–
[ ]: HDS Parameter

Malfunction Threshold
The return signal does not match the command to turn OFF shift solenoid valve B [Shift Sol B] for at least 1 second.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
Shift solenoid valve B SOL B line open (includes connector loose connection or disconnection)
Shift solenoid valve B internal circuit open
TCM internal circuit failure

Confirmation Procedure
Operating Condition
1.
Shift the transmission to P position/mode.
2.
Start the engine, and wait for at least 10 seconds.
With the HDS
None.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the TCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on, the shift position indicator blinks, and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The shift position indicator comes off by turning the vehicle to the OFF (LOCK) mode. The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.